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Publication numberUS5075174 A
Publication typeGrant
Application numberUS 07/560,520
Publication dateDec 24, 1991
Filing dateJul 31, 1990
Priority dateJul 31, 1990
Fee statusLapsed
Publication number07560520, 560520, US 5075174 A, US 5075174A, US-A-5075174, US5075174 A, US5075174A
InventorsJeffrey Pyle
Original AssigneeAcadia Polymers, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Parylene coated elastomers
US 5075174 A
Abstract
An improved elastomeric gasket comprising a silicone elastomer coated with a parylene layer is disclosed. The parylene is selected from one of the parylene C, parylene N,parylene D, and mixtures thereof and applied to reduce the surface energy of the elastomeric material.
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Claims(1)
What is claimed is:
1. A seal or gasket consisting of an elastomeric material comprising a silicone elastomer which has a layer of parylene coated on the outer surface thereof wherein the parylene is selected from the group consisting of parylene C, parylene N, parylene D and mixtures thereof and further wherein the layer has a thickness which is effective to reduce the surface energy of the elastomeric material which allows the seal or gasket to be employed in an electronic or computer environment.
Description
BACKGROUND OF THE INVENTION

The present invention relates to an improved elastomeric gasket which can be effectively employed in a variety of environments, particularly those environments, e.g., in computer and electronic equipment, in which traditional gaskets encounter a number of problems.

Seals or gaskets having a variety of shapes and sizes are employed throughout the computer and electronic industry. Because of the extreme sensitivity to contamination by particles having even minute proportions, these seals and gaskets must undergo an elaborate cleaning process in order to remove these particles. However, many of the elastomers employed have a high surface energy which serves to attract air borne particles and fibers. For this reason, it is very difficult and extremely expensive to provide adequate cleaning.

Moreover, when these gaskets are employed in a metal environment, e.g., in combination with a metal retainer for a contained volume, they are often subjected to surface bonding between the gaskets and the metal. This causes undesirable damage to the gaskets particularly in environments where the contained volume requires repeated openings.

Parylene has been employed in a variety of environments, e.g., in the computer and electronic industry as a coating for circuit boards, transducers, sensors, and microelectronic applications. See, for example, the discussion in NOVATRAN Custom Coating Services document entitled "Parylene Conformal Coating" which is incorporated herein by reference.

However, the need still exists for a gasket which can effectively overcome the problems described above.

SUMMARY OF THE INVENTION

In accordance with the foregoing objectives, the present invention relates to an improved seal or gasket. In particular, the seal or gasket consists of an elastomeric material having a desired shape which has a layer of parylene coated on the outer surface thereof wherein the parylene is selected from the group consisting of parylene-C, parylene-N, parylene-D or mixtures thereof and further wherein the layer has a thickness which is effective to reduce the surface energy of the elastomeric material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(a)-(d) illustrates a variety of cross-sectional shapes for seals or gaskets according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a seal or gasket which can be employed in a variety of environments, preferably in the electronics and computer industry. In particular, the gasket or seal of the present invention consists of an elastomeric material having a desired shape and which has a layer of parylene coated on the outer surface thereof.

The elastomeric material which can be employed within the present invention includes those elastomers which are known in the art, preferably, a silicone elastomer, nitrile elastomers, natural rubbers, fluorocarbon elastomers, styrene butadiene elastomers, ethylene-propylene elastomers, polyurethanes, neoprenes, polyacrylate elastomers, ethyl acrylates, fluorosilicone elastomers, highly saturated nitrile elastomers, and carboxylated nitrile elastomers, more preferably silicone elastomers. Mixtures of these elastomer, e.g., a mixture of natural rubber and styrene butadiene elastomers, can also be employed.

However, it is important to recognize that the selection of the elastomeric material to be employed is based upon the desired end use of the seal or gasket.

The shape and size of the gasket to be employed within the present invention is not critical as long as it can be effectively employed in the desired environment. However, the use of parylene allows for the uniform coating of gaskets having intricate shapes. See, for example, the shape illustrated by FIG. 1(d).

Other, typical shapes for the cross-section of the gasket include those illustrated in FIG. 1(a)-(c).

The product according to the present invention has a layer comprising at least one parylene coated on the outside thereof. Parylene is a generic name for a series of polymeric materials developed by Union Carbide Corporation.

Specific examples of the parylenes which can be employed in the present invention include parylene N, which is poly-p-xylylene, parylene C, in which a chlorine atom has been substituted for one of aromatic hydrogens and parylene D which includes 2 chlorine atoms substituted onto the aromatic group. ##STR1## The seal or gasket according to the present invention can be provided by coating the elastomeric material by any technique which is recognized in the art. For example that method discussed in the NOVATRAN Custom Coating Services document entitled "Parylene Conformal Coating Systems" which is incorporated herein by reference can be employed.

The coating layer has a thickness which is effective to reduce the surface energy of the elastomer, preferably this thickness ranges from 0.1 to 3 microns, most preferably 0.5 to 2 microns.

The product according to the present invention has a number of advantages over traditional seals and gaskets. In particular, the gasket according to the present invention has a significant reduction in outgassing when compared to non-coated elastomeric materials. This is particularly important when the seals or gaskets are used in proximity of or for isolation of computer and electronic equipment.

Because the coating effectively alters the surface energy of the elastomeric materials, airborne particles and fibers are no longer attracted thereto. It also is effective in altering the adhesion properties of the elastomers in order to prevent the undesirable sticking of the gasket or seal on to metal equipment.

The following examples illustrate the advantages which can be associated with the present invention and are understood to be illustrative and not limitive.

EXAMPLES Comparative Example 1

Samples 1-3 all relate to uncoated silicone elastomer gaskets which have been subjected to the post-bake conditions set forth in Table I and which are tested at 150 C. for 24 hours at 0.10 torr. The outgassing results associated therewith are illustrated in Table I.

              TABLE I______________________________________  Postbake   Total Mass                       Condensible OutgassedSample Conditions Loss (%)  Products (%)______________________________________1      None       1.397     0.7442      4 Hrs, 400 F.             0.537     0.293  1 atm3      4 Hrs, 200 F.             1.218     0.646  1 torr______________________________________
EXAMPLE 2

Samples 4-7 relate to elastomer gaskets according to the present invention which have all been coated with parylene and samples 4-6 have been post-baked for 4 hours at 400 F. prior to coating. The cleaning conditions for each of the samples are set forth in Table II.

              TABLE II______________________________________ Cleaning     Total Mass                        Condensible OutgassedSample Conditions   Loss (%)  Products (%)______________________________________4     cleaned and  0.127     0.030 primed5     cleaned, no  0.113     0.027 primer6     plasma clean 0.106     0.0407     12 Hr. vacuum              0.109     0.028 prebake______________________________________

As can be seen by a comparison between the data presented with in Tables I and II, both the total mass loss and the condensible outgassed products are significantly decreased for the product according to the present invention when compared with the uncoated materials.

While the invention is described in terms of various preferred embodiments, the artisan will appreciate the various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be defined solely by the scope of the following claims including equivalents thereof.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US4214119 *May 3, 1978Jul 22, 1980General Electric CompanyCorrosive resistant seal for epoxy shell bushings, method of providing same, and gasket therefor
US4375290 *Nov 24, 1980Mar 1, 1983Westinghouse Electric Corp.Sliding compression air seal for removable electronic units
US4500562 *Mar 2, 1983Feb 19, 1985The United States Of America As Represented By The United States Department Of EnergyDi-p-xylylene polymer and method for making the same
US4518623 *Apr 27, 1984May 21, 1985Riley Thomas JPolymeric film coating method with continuous deposition pressure control
US4580794 *Nov 16, 1984Apr 8, 1986Jamak, Inc.Silicon rubber gasket and material
US4862967 *Jul 18, 1988Sep 5, 1989Baker Oil Tools, Inc.Method of employing a coated elastomeric packing element
Non-Patent Citations
Reference
1Microcontamination, Jan. 1985, "Very Thin Coating for Contamination Control" by Roger Olson and Richard Veague.
2 *Microcontamination, Jan. 1985, Very Thin Coating for Contamination Control by Roger Olson and Richard Veague.
3 *Novatran Corporation Parylene Conformal Coating Systems . Novatran Corporation Solvent Resistance of the Parylenes .
4 *Novatran Corporation Parylene for Electronics .
5Novatran Corporation--"Parylene Conformal Coating Systems". Novatran Corporation--"Solvent Resistance of the Parylenes".
6Novatran Corporation--"Parylene for Electronics".
7 *Novatran Custom Coating Services Parylene Conformal Coating .
8Novatran Custom Coating Services--"Parylene Conformal Coating".
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US6070882 *Nov 18, 1997Jun 6, 2000Kokusan Parts Industry Co., Ltd.Sealing structure
US6129360 *Jan 29, 1997Oct 10, 2000Wacker Silicones CorporationAnti-bleed coating for silicone automobile gaskets
US6213805 *Oct 8, 1998Apr 10, 2001Hans JedlitschkaBoot/ring for high voltage connector and high-voltage connector obtained
US6270872May 17, 1999Aug 7, 2001Schering-Plough Healthcare Products, Inc.Parylene coated devices with adhesive
US6488992Aug 18, 1999Dec 3, 2002University Of CincinnatiProduct having a thin film polymer coating and method of making
US6493960Dec 5, 2000Dec 17, 2002Cardiac Pacemakers, Inc.Parylene coated desiccant sheet with activation strip
US6497416 *Dec 17, 1996Dec 24, 2002John D. MorvantWire inserted non-extrusion ring
US6586048 *Apr 5, 2001Jul 1, 2003Honeywell International Inc.Method for depositing a barrier coating on a polymeric substrate and composition comprising said barrier coating
US6699394 *Dec 22, 2000Mar 2, 2004California Institute Of TechnologyMicromachined parylene membrane valve and pump
US6997179Jan 13, 2004Feb 14, 2006Essex Pb&R CorporationProtective hood
US7455106Sep 7, 2005Nov 25, 2008Schlumberger Technology CorporationPolymer protective coated polymeric components for oilfield applications
US20050008848 *Dec 5, 2003Jan 13, 2005Saccomanno Robert J.Barrier coating composition for a substrate
US20060032498 *Jan 13, 2004Feb 16, 2006Niemann Bradley QImproved protective hood
US20060041190 *Aug 19, 2005Feb 23, 2006Pentax CorporationOperation button for endoscope
US20070051510 *Sep 7, 2005Mar 8, 2007Veneruso Anthony FPolymer protective coated polymeric components for oilfield applications
EP0764681A1 *Sep 26, 1996Mar 26, 1997Wacker-Chemie GmbHAnti-bleed coating for silicone automobile gaskets
WO2007128797A1 *May 4, 2007Nov 15, 2007Momentive Performance Materials Gmbh & Co. KgUse of coated silicone elastomers as membranes
Classifications
U.S. Classification428/447, 277/652, 428/523, 257/E23.193, 428/492
International ClassificationC08J7/04, H01L23/10
Cooperative ClassificationY10T428/31938, Y10T428/31663, Y10T428/31826, H01L2924/0002, C08J2465/00, H01L23/10, C08J7/047
European ClassificationC08J7/04L, H01L23/10
Legal Events
DateCodeEventDescription
Jan 2, 1991ASAssignment
Owner name: ACADIA POLYMERS, INC., 1420 COULTER DR., N.W., ROA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:PYLE, JEFFREY;REEL/FRAME:005552/0900
Effective date: 19901207
Jul 16, 1991ASAssignment
Owner name: JM CLIPPER POLMERS CORPORATION
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:ACADIA POLYMERS, INC., A CORP. OF NV;CONNECTICUT NATIONAL BANK;REEL/FRAME:005770/0528
Effective date: 19910701
Apr 17, 1995ASAssignment
Owner name: FIRST NATIONAL BANK OF BOSTON, THE, AS AGENT, MASS
Free format text: SECURITY INTEREST;ASSIGNOR:ACADIA POLYMERS CORPORATION, A DE CORP.;REEL/FRAME:007437/0352
Effective date: 19950406
Aug 1, 1995REMIMaintenance fee reminder mailed
Dec 24, 1995LAPSLapse for failure to pay maintenance fees
Feb 27, 1996FPExpired due to failure to pay maintenance fee
Effective date: 19951227
Nov 3, 2004ASAssignment
Owner name: ACADIA POLYMERS CORPORATION, VIRGINIA
Free format text: FULL RELEASE OF SECURITY AGREEMENT;ASSIGNOR:FLEET NATIONAL BANK (F/K/A BANKBOSTON, N.A.);REEL/FRAME:015320/0201
Effective date: 20041015